Generally, a transparent conductive film has been used for necessary constitutions of electric and electron devices, such as, power applications of display devices, an electromagnetic interference shielding film of home appliances, transparent electrodes in various kinds of display fields such as LCD, OLED, FED, PDP, flexible display, electronic paper, and the like. As a material for the transparent conductive film currently used, an inorganic oxide conductive material such as indium-tin oxide (ITO), antimony-tin oxide (ATO), antimony-zinc oxide (AZO), or the like is mainly used.
When the transparent conductive film is manufactured by a sputtering method, an ion beam method, a vacuum deposition method, or the like, conventionally using the above materials, there can be manufactured a conductive film having high conductivity and excellent transmittance. However, facility investment cost is high due to a vacuum apparatus; the transparent conductive films are difficult to mass-produce and be larger; and the transparent conductive film has a limit in a transparent substrate requiring a low-temperature process, such as, particularly, a plastic film.
At the time of deposition by the sputtering process, the composition of the transparent conductive film is varied depending on the conditions such as oxygen partial pressure, temperature, and the like, resulting in rapidly changing transmittance and resistance of the thin film.
Thus, a method of using a transparent conductive film is suggested, the transparent conductive film being manufactured by performing coating using a wet coating method such as spin coating, spray coating, deposition coating, printing, or the like, which is appropriate for low cost and a large size, and then performing burning. For example, Korean Patent Laid-Open Publication No. 1999-011487 discloses a transparent conductive film using a metal fine particle and a binder; Korean Patent Laid-Open Publication No. 1999-064113 discloses a composition for a transparent conductive film, obtained by adding a hollow type carbide fine fiber to tin oxide; and Korean Patent Laid-Open Publication No. 2000-009405 discloses a coating solution for forming a transparent conductive type photo-selective absorbing film, obtained by adding neodymium oxide to tin oxide or indium oxide. In addition, Japanese Patent Laid-Open Publication No. 2003-213441 discloses a method for preparing a solution for forming a transparent conductive layer, containing a metal fine particle of gold, silver, or the like.
The transparent conductive films manufactured by the above methods have high sheet resistance; fail to maintain initial conductivity due to occurrence of aging characteristics, such as, surface resistance increases with the passage of time by the change in surrounding environments; are limited in the use of a transparent conductive film due to low transmittance; and exhibits deteriorated productivity due to complicated processes and lots of processes.